Revert revert of protobuf
diff --git a/third_party/protobuf b/third_party/protobuf
index d5fb408..a1938b2 160000
--- a/third_party/protobuf
+++ b/third_party/protobuf
@@ -1 +1 @@
-Subproject commit d5fb408ddc281ffcadeb08699e65bb694656d0bd
+Subproject commit a1938b2aa9ca86ce7ce50c27ff9737c1008d2a03